Deleting a message stuck in the Outbox
There are instances when you try sending an email, and the sending fails. This could occur due to various reasons like error in the network connection, oversized attachment, etc. When something like this happens, the message will be present in the Outbox folder. If you attempt to delete this message, you might come across an error message which says that a MAPI spooler has started sending the message. It therefore becomes impossible to get rid of the mail in the Outbox folder.
There are some options that you can try out to delete the email in the Outbox. The first thing you can do, is to switch Outlook into the Offline mode and then try deleting the message. You can do this by selecting the Work Offline option from the File Menu as shown in the diagram below.
Once Outlook is in the Offline mode, try deleting the message from the Outbox folder. If you are still not able to delete the message from the Outbox, you can follow the steps given below to delete the message,
This procedure is safe provided that you do not commit silly mistakes and end up deleting the wrong email. There are also chances of the old pst file getting corrupted when you try to select the old pst file, to continue using it. In such cases, it is important to stay calm, and make use of a good Outlook recovery software. Repair Outlook PST File software lets you recover deleted/lost data from the most severe data loss situation.